1. Field of the Disclosure
The present invention relates to a semiconductor device and an apparatus for manufacturing the same, more particularly, to a CMOS image sensor and a method of and apparatus for manufacturing the same.
2. Discussion of the Related Art
In general, image sensors are semiconductor devices that convert optical images into electrical signals. Image sensors may be categorized into a charge coupled device (CCD) type and a complementary metal-oxide-silicon (CMOS) type. The image sensor includes a light receiving region having a photodiode for sensing incident light and a logic region for processing the sensed light into an electric signal for data formation.
FIG. 1 is a cross-sectional view illustrating a conventional CMOS image sensor. According to the conventional CMOS image sensor shown in FIG. 1, a light receiving region having a photodiode is illustrated, but not an entire logic region.
In reference to FIG. 1, the conventional image sensor includes a plurality of photodiodes 113 formed on a substrate 110, one or more interlayer dielectric layers 115 formed on the photodiodes 115, a planarization layer 130 formed on the interlayer dielectric 115, a color filter layer 140 formed on the planarization layer 130 having a plurality of color filters, each corresponding to an underlying photodiode 115, and a microlens 150 formed on each color filter in the color filter layer 140. Here, the interlayer dielectric 115 has a plurality of metal line layers 120.
Generally, light 105 passes through the microlens 150, the color filter layer 140 and the interlayer dielectric 115 sequentially. The light reaches the photodiode 115 corresponding to the microlens 150. The light having reached the photodiode 115 is absorbed in the substrate 110, and the absorbed light is converted into an electric signal.
The refractive index of silicon forming the photodiode 115 is approximately 4˜5 in a visible ray region. About 20˜30% of the light 105 that reaches the photodiode 115 may be reflected. Sensitivity of the image sensor may be less than optimum because the light 105 is reflected and scattered by the metal line layer 120. In addition, the light reflected and scattered by the metal line layer 120 may enter a neighboring photodiode and cause crosstalk.